Method of producing a glass-reinforced plastic article



29, 195 J. W. CASE 2,90%656 METHOD OF PRODUCING A AGLASS-REINFORCEDPLASTIC ARTICLE Original Filed Oct. 4. 1954 i fm. 2

-2; *qu f j E@ x "l" umm" INVENTOR JAMES t cA se ATTORNEYJ 2,906,656Patented Sept. 29, 1959 METHOD F PRODUCING A GLASS-REINFORCED PLASTICARTICLE James W. Case, Fairfax, Va.

Continuation of application Serial No. 460,281, October 4, 1954. Thisapplication November 16, 1956,`Serlal N0. 622,716

(Granted under Title 35, U.S. Code (1952), sec. 266) i `inforced plasticsheet or panel.

My copending application Serial No. 338,924, led February 25, 1953,discloses and claims a method and apparatus for coating such glass bersas they emerge from a glass furnace. Patent No. 2,758,951 is directed tothe plastic product. The present application is a continuation ofapplication Serial No. 460,281, filed October 4, 1954, for Method ofProducing a Glass-Reinforced Plastic Article, now abandoned, and isdirected to the Other objects and many of the attendant advantages ofthis invention will be readily appreciated as the Vsanne becomes betterunderstood by reference to the following detailed description whenconsidered in connection with 5 the accompanying drawings wherein:

method of arranging the bers in a particular relationship, sucharrangement and relationship imparting strength, toughness, durability,and a higher glass content for a given thickness of product.

An object of the invention is to provide a method for the manufacture ofplastic board, or plastic laminate, in which a novel step comprises themethod of arranging and interrelating ,the reinforcing glass bersincorporated in -the product.

A second object of the invention is to provide `a method of arranging aplurality of reinforcing glass bers of varying thicknesses in aparticular relation one to another so that the fibers of smallerthickness are interposed between adjacent bers of greater thickness butin offset disposition with respect to lines joining said 5 adjacentfibers at their central axes.

A third object is to provide a method of producing varyingcross-sectional area and so interrelated as to produce maximum glasscontent within the connes of the finished product.

A fourth object is to provide a' method for the manufacture of plasticboard, or plastic laminate, which method involves drawing from a glassfurnace successive series V`of molten glass bers of varyingcross-sectional areas, winding said successive series of bers upon areceiving drum, until the number of wound layers produces a desiredthickness of glass upon the drum, then removing all of the glass fromthe drum by a longitudinal cut through all the layers, to permit thewound glass layers to be laid out on a plane surface, in the form of amat, and finally applying to said glass mat a quantity of liquid fillermaterial suicient to unite the glass bers into a single plastic entityby the penetration of the liiglerid iiller into all of the spacesbetween successive a plastic product incorporating a plurality of glasscyl- Y inders of reinforcing material, the cylinders being of Figs. land 2 are front and end elevation views, respectively, of apparatusapplicable to the practice of the invention; I

Fig. 3 is a plan view of the furnace bushing of Figs. 1 and 2, theorifice diameters being shown on a greatly magnified scale; and

Fig. `4 is a similarly exaggerated sectional view of a plastic unit madeby the method herein disclosed, utilizing the apparatus illustrated inFigs. 1, 2 and 3.

In Figs. l and 2 numeral 10 denotes a glass furnace containing moltenglass. The glass is drawn as filaments 13 from a bushing 12 whosedetails are better shown in Fig. 3. Referring to said Fig. 3 the bushingis there shown as provided with a series of relatively large alignedorices 5 and a series of smaller orices 6 in staggered and interstitialrelation to the orices 5, but in sufiiciently close proximity tomaintain all orices within the limits of a straight line having tangencywith the larger orices 5, so that the glass bers 13 drawn through theseorifices will all be disposed in a single array or sheet form andtherefore will lie smoothly and evenly upon the cylindrical surface ofthe drum 30 (Figs. 1 and 2) after passing through the coating chamber 20where they receive a coating of metal or other bond tolerating material,as described more fully in my copending application Serial No. 338,924,mentioned hereinbefore. The drum is motor driven in a manner well-knownin the art. When the winding method has continued long enough to producethe desired number of layers of glass fibers upon the drums surface, thedrums rotation is interrupted and the glass mat is removed therefrom bya longitudinal slitting operation, with the cutting instrumentpenetrating all layers. The method is repeated to form additional glassmats, after which the desired number of mats are superimposed andintegrated with a liquid plastic material whereby the superimposed glassmats are converted into a unitary, glass-reinforced plastic board, orlaminate, after the plastic binder material has had time to acquire apermanent set. Inassembling successive mats to form .the completelaminated board, the mats may be turned selectively to establishdifferent angular relationships between the parallel fibers of one mat,and those of the mats immediately above and below. In this manner thestrength of the completed board will be increased, and will approachuniformity of strength and resistance to bending or breaking forcesapplied thereto from any direction. Also, if desired, the successiveglass-filled laminate may be interleaved with laminae of othercompositions, such as plastic sheets having other kinds of reinforcingfabrics, or no reinforcing material whatever, so that in the completedboard the glass-filled layers may be in spaced relationship, in a crosssection through the board rather than contiguous.

As each glass mat includes a plurality of layers of the glass bers 13,it will be apparent that the drum 30 will make many revolutions beforeaccumulating a sufcient thickness of glass to form one of the mats; andwhile the mat illustrated in Fig. 4 is shown as having only three suchlayers it is to be understood that this is a purely schematicillustration, and that actually there may be hundreds of layers of thefilament 13 in each individual mat. The actual diameter of even therelatively large orices 5 is on the order of just a few thousandths ofan inch with that of the smaller orices 6 being correspondingly less.

Obviously many modifications and variations of the present invention arepossible in the light of the above teachings.- It is therefore to beunderstood that within the scope of the appended claims the inventionmay be practiced otherwise than as specically described.

What is claimed is:

1. The method of producing a glass-reinforced plastic article whichcomprises melting batch material to form a mass of molten glass,separating the mass into adjacently situated individual laments of smalland large cross-sectional areas, positioning the laments of the smallercross-sectional areas between the laments of the larger cross-sectionalareas to form a sheet of parallel substantially alined laments ofalternating crosssectional areas, hardening the filaments in theirarranged sheet position, winding said sheet to form acoil of a series ofsuperimposed layers, slitting the coil longitudinally and reverselyrolling it to form a mat, and impregnating the remaining spaces betweenthe laments with a plastic.

2.` lIhe method of producing a high glass content glassreinforcedlaminated plastic article which comprises moving a mass of molten glassto a laminating area, separating the mass into adjacently situatedindependent laments of alternate small and large cross-sectional areas,and simultaneously arranging the separated laments so that the lamentsof the smaller cross-sectional areas occupy the interstices between thefilaments of the larger cross-sectional areas, hardening the laments intheir arranged positions,iwinding said filaments in their .arrangedpositions to form a coil of a series of superimposed layers, slittingthe coil longitudinally and reversely rolling it to form a mat, andimpregnating the remaining spaces between the laments with a plastic.l

3. The method of producing a compact glass-reinforced laminated matwhich comprises moving a mass of molten glass to a laminating area,separating the mass into adjacently situated independent laments ofsmall and large crossJsectional areas, and simultaneously positioningthe laments of the smaller cross-sectional areas between the laments ofthe larger cross-sectional areas to form a sheet of parallel laments ofalternating crosssectional areas, hardening the laments in theirarranged sheet position, and collecting a plurality of said sheets insuperimposed relationship to form a mat.

4. The method of producing a compact glass-reinforced structure whichcomprises moving a mass of molten glass to a separating area, separatingthe mass into adjacently` situated independent lamcnts of small andlarge cross-sectional areas, and simultaneously positioning a pluralityof the filaments of the smaller crosssectional areas between the lamentsof the larger crosssectional areas to form a sheet of parallel lamentsof -alternating cross-sectional areas, maintaining uniform spacingbetween the laments throughout their lengths, and hardening the lamentsin such uniformly spaced condition to provide a sheet.

5. The method of making a plastic article with a high glass reinforcingcontent comprising; forming a molten glass batch material, separatingsaid batch material into continuous laments of respectively small andlarge cross sectional areas, arranging the small and large iilaments inadjacent alternate parallel relationship to form a rst sheet, drawingthe continuous and arranged laments to form a second sheet, positioningsaid second sheet upon said rst sheet with the large `laments of saidrst sheet contiguous with the small Ifilaments of said second sheet andvice versa to form a mat and vimpregnating said mat with a bondingmaterial to produce a unitary article.

6. 'Ihe method of producing a high glass content plastic article from amolten glass batch comprising; forming a plurality of glass bers ofrespectively small and large cross-sectional areas, simultaneouslyarranging said -bers into a continuous lm with the large and small bersinterspersed in alternate adjacent positions, placing said lm upon arotatable ber drawing drum, accumulating successive lengths of-the lmupon said drum, simultaneously positioning said successive lengths ofthe lm so that the large and small bers thereof will lie adjacent thesmall and large bers respectively of the next preceding length of filmto form a mat, slicing the mat axially of the drum and impregnating themat with a plastic to form a unitary article.

7. The method of producing a compact glass reinforced plastic structurecomprising the steps of: arranging small and large glass bersalternatelysubstantially in line so that two small bers will separate each largeber to form a sheet, placing said sheet upon a rotatable ber drawingdrum, rotating said drum to form additional sheets of alternately placedsmall and large bers, accumulating the additional sheets upon said drumin successive layers, simultaneously positioning the additional sheetsto place -the large bers thereof in contiguous relation with respect tothe small bers of the next adjacent sheet to form a mat of diterentsized adjacent bers in substantially parallel relationship, cutting themat axially of the drum and impregnating said mat with a plastic to forma unitary structure.

References Cited in the le of this patent UNITED STATES PATENTS2,262,871 Whitehead Nov. 18, 1941 2,408,713 Webb Oct. l, 1946 2,461,094Taylor Feb. 8, 1949 2,565,941 Barnard Aug. 28, 1951 2,574,221 ModiglianiNov. 6,1951 2,699,415 Nachtman Jan. 11, 1955 2,728,699 Labino Dec. 27,1955

1. THE METHOD OF PRODUCING A GLASS-REINFORCED PLASTIC ARTICLE WHICHCOMPRISES MELTING BATCH MATERIAL TO FORM A MASS OF MOLTEN GLASS,SEPARATING THE MASS INTO ADJACENTLY SITUATED INDIVIDUAL FILAMENTS OFSMALL AND LARGE CROSS-SECTIONAL AREAS, POSITIONING THE FILAMENTS OF THESMALLER CROSS-SECTIONAL AREAS BETWEEN THE FILAMENTS OF THE LARGERCROSS-SECTIONAL AREAS TO FORM A SHEET OF PARALLEL SUBSTANTIALLY ALINEDFILAMENTS OF ALTERNATING CROSS-